48. Polystichum thomsonii (J. D. Hooker) Beddome, Ferns Brit. India. 1: t. 126. 1866.
尾叶耳蕨 wei ye er jue
Aspidium thomsonii J. D. Hooker, Cent. Ferns, t. 25. 1860; Dryopteris thomsonii (J. D. Hooker) Kuntze; P. silaense Ching.
Plants summer-green. Rhizome erect, short, densely scaly at apex; scales brown, broadly ovate and acute, or narrowly ovate or ovate-lanceolate and shortly acuminate, up to 7 × 4 mm, margins shortly fimbriate or only with short teeth. Fronds 8-50 cm; stipe stramineous, 2-20 cm, 0.5-1.5 mm in diam., large scales on basal stipe similar to rhizome scales; small scales brown, lanceolate or narrowly lanceolate, membranous, margins long fimbriate, distal stipe scales sparser toward rachis apex. Lamina 1-pinnate, abaxially light yellowish green when dry, adaxially darker, lanceolate, 5-33 × 1-5 cm, base often slightly contracted, apex long acuminate or caudate; rachis stramineous, without proliferous bulbils, sparsely scaly abaxially; scales similar to distal stipe scales. Pinnae 10-25 pairs, attached at nearly right angles to rachis, alternate, shortly stalked, stalks with decurrent narrow wings on both sides, obliquely ovate, 0.5-2.5 cm × 2-12 mm, bases asymmetrical, acroscopic base auriculate, basiscopic margins oblique, pinnatifid to pinnatisect, apices acute. Lobes 2-7 pairs, basal acroscopic auriculate lobes largest, ovate, pinnatilobate to pinnatifid, basal basiscopic lobes and sometimes also second lobes of acroscopic base pinnatilobate, all lobes angled upward, apices acute, slightly recurved; both surfaces sparsely scaly; microscales brown, long acicular; frond texture papery; venation pinnate, distinct abaxially, slightly visible adaxially, veinlets simple or unequally forked on primary and secondary lobes, clavate apically. Sori abaxial on veinlets or terminal on shorter veinlets, close to midrib, basalmost pinnae often sterile; indusia present, large, membranous, with shallow rounded teeth or erose, centers slightly concave, brown when mature. Spores semicircular in equatorial view; perispore sculpturing plicate.
Cliffs and rock crevices in montane broad-leaved forests, mixed broad-leaved coniferous forests, Abies forests; 2000-3900 m. S Gansu, Guizhou (Fanjing Shan, Hezhang), W Sichuan, Taiwan, E Xizang, Yunnan [Afghanistan, Bhutan, NE and NW India, Kashmir, N Myanmar, Nepal, Pakistan].